The present invention relates to an electric vacuum cleaner.
An electric vacuum cleaner which is transformable depending on places to be cleaned is disclosed in Japanese Unexamined Utility Model Publication No. 80455/1992, wherein the electric vacuum cleaner is of concurrent type which can be used in an upright condition for use by fastening a vacuum cleaner body to a support pipe in a attachable/detachable manner and which can also be used in a condition where the vacuum cleaner body is detached from the support pipe.
Such a conventional concurrent type vacuum cleaner comprises, as shown in FIG. 21, a vacuum cleaner body 31, a hose 40, a support pipe 32, a rotary bend 33 and a suction device 34. By sequentially connecting these components, there is achieved a condition where the vacuum cleaner body is detached from the support pipe wherein the vacuum cleaner body 31 and the support pipe 32 are separated.
The rotary bend 33 is connected to the suction device 34 (or a rotary pipe (not shown) connected to this suction device 34) in a rotatable manner.
Further, by fitting projections 36 provided on the outer surface of the support pipe 32 to concave portions 35 formed on the lower surface of the vacuum cleaner body 31, the lower surface of the vacuum cleaner body 31 can be fastened to the support pipe 32, whereby the vacuum cleaner can be transformed into an upright condition for use as shown in FIG. 21. When assuming the upright condition for use, the vacuum cleaner body 31 is leaning against the support pipe 32 and abuts onto the suction device 34. In the upright condition for use, the hose 40 is so arranged that the upper end thereof is connected to a position substantially below a grip 37 in the rear side of the support pipe 32, an intermediate portion thereof is winding from the side of the support pipe 32, and the lower end thereof is connected to the vacuum cleaner body 31 in the front side of the support pipe 32. It should be noted that 31a denotes a portion at which rear wheels 38 at a rear portion of the lower end of the vacuum cleaner body 31 are provided.
There are formed at least two concave portions 35 on the lower surface of the vacuum cleaner body 31 along a front and rear direction of the vacuum cleaner body 31, and a plurality of projections 36 are provided along a vertical direction of the support pipe 32 so as to correspond to the respective concave portions 35.
However, according to this conventional art, the front and rear wheels of the suction device and the rear wheels of the vacuum cleaner body contact the ground in the upright condition for use. Since six wheels simultaneously contact the ground in this arrangement, change in running directions when performing cleaning operation is hard to be made, whereby the cleaning workability is made poor. It is further presented a drawback, in a condition where the vacuum cleaner body is detached from the support pipe, that the rear wheels of the vacuum cleaner body largely project rearward and look unattractive.
A conventional vacuum cleaner is also arranged in such a manner that the rotary bend 33 can be rotated with respect to the suction device 34 in the upright condition for use. In addition, the center of gravity of the vacuum cleaner body 31 attached to the upper surface of the support pipe 32 is located above a rotating axis (that is, a position corresponding to a central axis of a connecting portion 39 of the rotary bend 33 and suction device 34).
Therefore, when the support pipe 32 and rotary bend 33 are slightly inclined to a vertical direction in FIG. 21 as to rotate with respect to the suction device 34, continuous force in a rotating direction is applied to an users hand holding the grip 37 in the upper portion of the support pipe 32 and is thus quite unstable which also leads to poor workability.
On the other hand, while this problem can be solved by an arrangement in which the rotary bend 33 is preliminarily fastened to the suction device 34 so that it cannot rotate, such an arrangement would limit the sphere of usage and be undesirable, since, for instance, the suction device 34 can no longer be inserted into narrow spaces such as under a bed in which the rotary bend 33 is in a condition where it is rotated so as to be parallel to the floor surface with the vacuum cleaner body being detached from the support pipe.
The conventional electric vacuum cleaner of FIG. 21 also presents a drawback that it is difficult to fix the vacuum cleaner to the support pipe since the plurality of projections 36 aligned in the upper and lower ends of the vacuum cleaner body need to be simultaneously fitted to the concave portions 35.
Further, during the detaching process, the vacuum cleaner body 31 might loose its stability in a case where only the projection 36 on the lower side is fitted to the concave portion 35, since the front side of the vacuum cleaner body 31 would then not be fixed to the support pipe 32.
A conventional vacuum cleaner in its upright condition for use is so arranged that a portion in the proximity of the upper end of the hose 40 projects from below the grip 37 to rearward of the support pipe 32. This arrangement presents a drawback in that the vacuum cleaner body is hard to use since the hose 40 contacts the user in a rubbing manner.
The present invention has been made in view of solving these problems, and it is an object of the present invention to provide an electric vacuum cleaner having improved cleaning workability and a vacuum cleaner body of improved external appearance when it is detached from the support pipe.
It is further an object of the present invention to provide an electric vacuum cleaner which can be easily operated in an upright condition for use by preventing the rotary bend which receives the load of the vacuum cleaner body from rotating relative to the rotary pipe at a side of the suction device, and moreover, of which sphere of usage is not limited by permitting rotation in a condition where the vacuum cleaner body is detached from the support pipe.
It is also an object of the present invention to provide an electric vacuum cleaner of which vacuum cleaner body can be easily attached to/detached from the support pipe.
It is another object of the present invention to provide an electric vacuum cleaner in which the stableness of the vacuum cleaner body during the attaching/detaching process is improved.
It is still another object of the present invention to provide an electric vacuum cleaner in which the hose in the upright condition for use can be smoothly operated without contacting the user.